Compression ignition controlled free piston-turbine engine

Abstract

A fuel injected free piston-turbine heat engine wherein a piston moves reciprocally within a cylinder to deliver gases to an impulse turbine powering a fan-scavenged two-stroke cycle operation of said piston, there being a low compression storage chamber of substantial volume normally open into the cylinder and closed by upward movement of the piston to withhold gases at combustion supporting temperature, there being a high compression auto ignition chamber of limited volume comprising the upper portion of the cylinder and isolated from said low compression chamber by said piston closure thereof for continued compression of combustion supporting gases by said piston movement to auto ignition temperature, and there being constant volume fuel injection means for injecting fuel at high pressure into the auto ignition chamber and at a progressively diminishing rate as the first mentioned storage chamber is re-opened and as the cylinder pressure decreases during the effective power stroke.

I claim: 
     
       1. A compression ignition and controlled diminishing pressure free piston-turbine scavenged heat engine wherein a double headed piston reciprocates between opposite closed heads of a cylinder and is acted upon by the expansion of burning fuel to apply pressure to opposite heads of the piston and perform work in the form of exhaust heat and torque from said turbine, and including; diametrically opposite laterally opening exhaust and inlet ports spaced from each cylinder head and uncovered by opposite heads of the piston moving through the ends of its power stroke in each instance for two cycle loop scavenging operation, gas discharge ports intermediate the exhaust and inlet ports and the opposite ends of the cylinder for receiving compression and combustion gases from opposite cylinder chambers, auto ignition chambers of minimized volume between said discharge ports and opposite heads of the cylinder of compression of gases to ignition temperature, turbine means alternately receiving compression and combustion gases from said discharge ports respectively, blower means operated by said turbine means and pumping scavenge air through said inlet ports when they are uncovered by the piston for said loop flow scavenging, and a full stroke fuel pump means injecting fuel through opposite heads of the cylinder in timed relation to the piston reaching peak compression positions and continuing injection substantially throughout alternate work strokes respectively. 
     
     
       2. The compression ignition and controlled diminishing pressure free piston-turbine scavenged heat engine as set forth in claim 1, wherein the gas discharge ports open high into the opposite cylinder chambers and closed by piston movement toward opposite heads of the cylinder to establish said auto ignition chambers respectively. 
     
     
       3. The compression ignition and controlled diminishing pressure free piston-turbine scavenged heat engine as set forth in claim 1, wherein the turbine means comprises at least one wheel reacting to the compression and combustion gases delivered through nozzle means from said discharge ports. 
     
     
       4. The compression ignition and controlled diminishing pressure free piston-turbine scavenged heat engine as set forth in claim 1, wherein the turbine means comprises separate wheels reacting to the compression and combustion gases delivered through nozzle means from each of said discharge ports opening from opposite cylinder chambers. 
     
     
       5. The compression ignition and controlled diminishing pressure free piston-turbine scavenged heat engine as set forth in claim 1, wherein the turbine means comprises at least one impulse turbine wheel reacting to the velocity of compression and combustion gases delivered through nozzle means from said discharge ports. 
     
     
       6. The compression ignition and controlled diminishing pressure free piston-turbine scavenged heat engine as set forth in claim 1, wherein the turbine means comprises separate impulse turbine wheels reacting to the compression and combustion gases delivered through nozzle means from each of said discharge ports opening from opposite cylinder chambers. 
     
     
       7. The compression ignition and controlled diminishing pressure free piston-turbine scavenged heat engine as set forth in claim 1, wherein the blower means is positive displacement and alternately delivers compression air through the inlet ports into opposite cylinder chambers. 
     
     
       8. The compression ignition and controlled diminishing pressure free piston-turbine scavenged heat engine as set forth in claim 1, wherein the double headed piston is highly domed at its opposite ends for directing said loop flow scavenging. 
     
     
       9. The compression ignition and controlled diminishing pressure free piston-turbine scavenged heat engine as set forth in claim 1, wherein probes enter the cylinder at the opposite peak compression positions of the piston, there being timed motor means responsive thereto and operating said full stroke fuel pump means. 
     
     
       10. The compression ignition and controlled diminishing pressure free piston-turbine scavenged heat engine as set forth in claim 1, wherein probes enter the cylinder at the opposite peak compression positions of the piston, there being timed motor means responsive thereto and operating said full stroke fuel pump means with control means restricting fuel injection throughout the power stroke. 
     
     
       11. The compression ignition and controlled diminishing pressure free piston-turbine scavenged heat engine as set forth in claim 1, wherein probes enter the cylinder at the opposite peak compression positions of the piston, there being timed motor means responsive thereto and operating said full stroke fuel pump means with control means variably restricting the rate of fuel injection to effect diminishing combustion pressures throughout the power stroke. 
     
     
       12. The compression ignition and controlled diminishing pressure free piston-turbine scavenged heat engine as set forth in claim 1, wherein probes enter the cylinder at the opposite peak compression positions of the piston, there being timed motor means responsive thereto and operating said full stroke fuel pump means with cam control means operated synchronously with operation of the engine and variably restricting the rate of fuel injection to effect diminishing combustion pressures throughout the power stroke. 
     
     
       13. A compression ignition and controlled diminishing pressure free piston-turbine scavenged heat engine wherein a double headed piston reciprocates between opposite closed heads of a cylinder and is acted upon by the expansion of burning fuel to apply pressure to opposite heads of the piston and perform work in the form of exhaust heat and torque from said turbine, and including; diametrically opposite laterally opening exhaust and inlet ports spaced from each cylinder head and uncovered by opposite heads of the piston moving through the ends of its power stroke in each instance for two cycle loop scavenging operation, closed storage chambers opening through transfer ports into the cylinder intermediate the exhaust and inlet ports and opposite heads of the cylinder for the exit and re-entry of gases from and into opposite cylinder chambers and said transfer ports being positioned for closure by the opposite piston heads and the entrapment of gases in said storage chambers at combustion supporting pressure, gas discharge ports intermediate the exhaust and inlet ports and the storage chamber ports for receiving compression and combustion gases from opposite cylinder chambers, auto ignition chambers of minimized volume between said discharge ports and opposite heads of the cylinder for compression of gases to ignition temperature, turbine means alternately receiving compression and combustion gases from said discharge ports respectively, blower means operated by said turbine means and pumping scavenge air through said inlet ports when they are uncovered by the piston for said loop flow scavenging, and a full stroke fuel pump means injecting fuel through opposite heads of the cylinder in timed relation to the piston reaching peak compression positions and continuing injection substantially throughout alternate work strokes respectively. 
     
     
       14. The compression ignition and controlled diminishing pressure free piston-turbine scavenged heat engine as set forth in claim 13, wherein the storage chamber transfer ports open high into the opposite cylinder chambers and closed by piston movement toward opposite heads of the cylinder to establish said auto ignition chambers respectively. 
     
     
       15. The compression ignition and controlled diminishing pressure free piston-turbine scavenged heat engine as set forth in claim 13, wherein the turbine means comprises at least one wheel reacting to the compression and combustion gases delivered through nozzle means from said discharge ports. 
     
     
       16. The compression ignition and controlled diminishing pressure free piston-turbine scavenged heat engine as set forth in claim 13, wherein the turbine means comprises separate wheels reacting to the compression and combustion gases delivered through nozzle means from each of said discharge ports opening from opposite cylinder chambers. 
     
     
       17. The compression ignition and controlled diminishing pressure free piston-turbine scavenged heat engine as set forth in claim 13, wherein the turbine means comprises at least one impulse turbine wheel reacting to the velocity of compression and combustion gases delivered through nozzle means from said discharge ports. 
     
     
       18. The compression ignition and controlled diminishing pressure free piston-turbine scavenged heat engine as set forth in claim 13, wherein the turbine means comprises separate impulse turbine wheels reacting to the compression and combustion gases delivered through nozzle means from each of said discharge ports opening from opposite cylinder chambers. 
     
     
       19. The compression ignition and controlled diminishing pressure free piston-turbine scavenged heat engine as set forth in claim 13, wherein the blower means is positive displacement and alternately delivers compression air through the inlet ports into opposite cylinder chambers. 
     
     
       20. The compression ignition and controlled diminishing pressure free piston-turbine scavenged heat engine as set forth in claim 13, wherein the double headed piston is highly domed at its opposite ends for directing said loop flow scavenging. 
     
     
       21. The compression ignition and controlled diminishing pressure free piston-turbine scavenged heat engine as set forth in claim 13, wherein probes enter the cylinder at the opposite peak compression positions of the piston, there being timed motor means responsive thereto and operating said full stroke fuel pump means. 
     
     
       22. The compression ignition and controlled diminishing pressure free piston-turbine scavenged heat engine as set forth in claim 13, wherein probes enter the cylinder at the opposite peak compression positions of the piston, there being timed motor means responsive thereto and operating said full stroke fuel pump means with control means restricting fuel injection to effect combustion pressures less than the storage chamber pressures. 
     
     
       23. The compression ignition and controlled diminishing pressure free piston-turbine scavenged heat engine as set forth in claim 13, wherein probes enter the cylinder at the opposite peak compression positions of the piston, there being timed motor means responsive thereto and operating said full stroke fuel pump means with control means variably restricting the rate of fuel injection to effect diminishing combustion pressures less than diminishing storage chamber pressures. 
     
     
       24. The compression ignition and controlled diminishing pressure free piston-turbine scavenged heat engine as set forth in claim 13, wherein probes enter the cylinder at the opposite peak compression positions of the piston, there being timed motor means responsive thereto and operating said full stroke fuel pump means with cam control means operated synchronously with operation of the engine and variably restricting the rate of fuel injection to effect diminishing combustion pressures less than diminishing storage chamber pressures.